This material is used in lessons within Teaching Algebra to the Adolescent: A Montessori Approach Volume 2. These lessons include - Sum of Squares, Sum of Natural Numbers, Sum of Cubes, Sum of Rectangular Numbers.
 
The wooden decanomial can help students develop formulas and understandings of patternistic thinking. While keeping the idea concrete, students can expound upon and move towards abstraction. 
 
There is a limited quantity available.